Dymola and the hydraulics library Hydraulics (formerly HyLib) allow you to optimize and verify the design of your hydrostatic drive system from the early design phases through control design and implementation. Contrary to special-purpose tools for the same type of simulations, Hydraulics has an open, object-oriented architecture so that all models can be inspected as source code in Modelica and customised to fit the individual user's needs. Dymola and Hydraulics are especially designed for multi-domain system modeling, e.g. hydraulics and electronics or multi-body mechanics.
Users can connect components freely as they desire, so it is easy to realize non-standard configurations such as two motors in series. The library models are based on extensive literature research, several years of experience and validation in advanced research applications and industrial projects. The models can also be used for real-time and hardware-in-the-loop applications.
Hydaulics is distributed by Dassault Systèmes.
Some Examples
The Excavator is a truly multi-domain, non-linear system. An excavator has several degrees of freedom that strongly influence one another. To get a realistic simulation model the dynamics of both mechanics and hydraulics have to be taken into account. The hydraulic system is controlled by a "load sensing" controller. Usually, models containing 3-dimensional mechanical and hydraulic components are difficult to simulate. The model of the excavator demonstrates that the Hydraulics Library and the Modelica language are well suited for such kinds of system simulations.
Some Technical Information
The Hydraulics Library contains the most important components,in order to model hydraulic circuits. Coupling elements exist to connect hydraulic components with blocks of the blocks library and elements of the Modelica.Mechanics library. This library supports the following types of models:
Modelling of 1-dimensional rotational and translational hydraulic systems.
As a state variable the pressure in a lumped volume is used. The inductance of a moving oil column can be added with the model Inductance.
Each component of the main library has a lumped volume connected at each port. The components can therefore be connected in any sequence.
Connection Rules for Elements
All elements of the main hydraulic library can be connected in an almost arbitrary way. As almost every component of the main library has a lumped volume at each port a model can be build by just connecting the appropriate library components. The user doesn't have to add lumped volumes at each node to model the pressure dynamics. A Modelica tool like Dymola will reduce the index of the resulting DAE and solve it.
Experienced users can use the additional Basic libraries that can be found in the main library. Those components haven't included lumped volumes at the ports and therefore the user has to add the required volumes or can use numerical solution of algebraic equations.
Publications
The Hydraulics Library has been used successfully in industry and academia for many years. The following publication list demonstrates the multi-domain capabilities of the Hydraulics Library when combined with other Modelica libraries:
Users can connect components freely as they desire, so it is easy to realize non-standard configurations such as two motors in series. The library models are based on extensive literature research, several years of experience and validation in advanced research applications and industrial projects. The models can also be used for real-time and hardware-in-the-loop applications.